Means and method of sewing sheet metal



Dec. 23, 1958 H. D. lHRlG MEANS AND METHOD OF SEWING SHEET METAL.

I5 Sheets-Sheet 1 Filed June 5, 1956 INVENTOR HAROLD.D IHRIG Dec. 23, 1958 H. D. IHRIG MEANS AND METHOD OF SEWING SHEET METAL Filed June 5, 1956 3 Sheets-Sheet 2 F IG.5

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INVENTOR. HAROL D D. IHRIG Dec. 23, 1958 H. D. lHRlG MEANS AND METHOD OF SEWING SHEET METAL 5 Sheets-Sheet 3 Filed June 5, 1956 waw United States Patent MEANS AND METHOD OF SEWIN G SHEET METAL Harold D. Ihrig, San Diego, Calif. Application June 5, 1956, Serial No. 589,485

4 Claims. (Cl. 164-109) This invention relates generally to machine tools and more particularly to a machine for interconnecting sheet metal elements.

It is known that the prior art includes various types of riveting machines wherein portions of sheet metal stock are deformed and used for connecting the portions together and no claim is made to invention of the broad concept of connecting two metal sheets together without use of separate rivet elements. The instant invention, is, however, concerned with the provision of improved punch and clincher block elements and the arrangement of the same with a bed plate and novel spacing and power driving means, whereby the process is generally improved over that accomplished by prior art machines.

A primary object of this invention, is therefore, to provide a machine for interconnecting sheet metal elements characteriezd by improved operational characteristics, such as the minimizing of deformation in the elements, and the prevention of the setting up of unwanted stresses in the metal immediately surrounding the portions which are physically interconnected.

Another object of this invention is to provide such a machine as will be suitable for construction in various sizes to handle a very wide range of thicknesses in the sheet metal elements being processed, this versatility being due in part to the fact that minimum power is required to effect the desired results by reason of the character of the parting and clinching operations.

Still another object of this invention is to provide a machine of the character mentioned above which is extremely simple to assemble and dismantle, when required, with a corresponding improvement in ease of maintenance and repair, and with maximum ease of replacement of portions which may become worn, the machine being not limited to the illustrated use of camoperated lever arms, since hydraulic means or other power means can well be used, especially in the larger machines.

Still another object of this invention is to provide, probably for the first time in the art, satisfactory means for spacing the advance of the work piece as it is being operated upon, while retaining the full advantages of easy insertion and withdrawal of the work piece from the machine.

A last object to be mentioned specifically is to provide a machine of the' general character mentioned above which is safe for the operator to handle, and which is extremely convenient and simple to use.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, aswill be hereinafter fully described in the specification, particu- "v larly pointed out in the claims, and illustrated in the drawings which form a material part of this disclosure, and in which:

Figure l is a view, in perspective, of the assembled machine, portions of one side plate being removed to show underlying structure and small portions of one of the arms and a portion of the frame being also removed for the same reason;

Figure 2 is a side elevational view of the machine with one side plate removed, and with sheet metal elements shown in vertical section, along with the bed plate which is also shown in vertical section;

Figure 3 is a fragmentary, enlarged view taken from the front end of the machine which will be considered the left hand end of the machine as shown in Figure 2, this Figure 3 being proposed as showing the position of the principal elements of the machine at the beginning of its cycle of operations when the work or work pieces have been placed in position and the punch as well as the clincher block are both fully retracted;

Figure 4 is a view, similar to Figure 3, and showing the punch in the position assumed at the end of its operative stroke;

Figure 5 is a view similar to Figures 3 and 4 and showing the next step in the cycle of operations, namely, the clinching of the segments between the anvil faces of the punch and the abutment faces of the clincher block, the latter being shown in its fully raised position, the work pieces and bed plate are shown, in Figures 3, 4 and 5, in vertical section in the plane of the front face of the punch;

Figure 6 is a view of a pair of sheet metal strap elements which have been interconnected by the instant machine, the view being fragmentary and perspective in character;-

Figure 7 is a fragmentary view of a front end portion of the machine with a proximate side plate removed and work piece elements in position and shown in vertical section, on the bed plate, this Figure 7 being proposed as showing the parts of the machine when the upper arm is at the bottom of its downward stroke and the lower arm fully raised;

Figure 8 is a view, similar to Figure 7 and showing how a catch on the upper arm after retracting the spacer pin and immediately after having released the same, the upper arm having reached its upper limit of travel and the spacer pin having been released for depression by its operating spring into one of the holes punched inthe Work pieces;

Figure 9 is a view, similar to Figures 7 and 8, and showing the upper arm at the beginning of its upward stroke the position of the catch in Figure 9 being its operative position beneath the sliding bracket of the spacer pin;

Figure 10 is a view, in perspective, of the punch and clincher block with the rails used to assure rectilinear movement of the punch and clincher block.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawings.

Referring now to the drawings in detail, this invention, in the embodiment thereof illustrated, includes, a

generally U-shaped frame having an upper portion 10, a

vertical rear portion 12 and a base 14. A pair of side plates 16 may be considered as a portion of the frame, since these side plates support an upper or punch-carrying arm 18 and a lower or clincher-carrying arm 20. The side plates are rigidly secured, by any suitable means, not shown, to the frame and a trunnion element 22 is provided for pivotal mounting of the upper arm 18 on the side plates 16, while a similar trunnion element 24 is provided for similar pivotal mounting of the lower arm.

The arms 18 and 20 are substantially coextensive in length with the frame and may be completely enclosed thereby, as shown. A strong spring 26 is compressed between the rear ends of the arms, the front of the machine being-.that-considered as shown at the lefthand end of the Figure l.

A smaller cam 28 for driving the lower arm and a larger cam 30 for driving the upper arm 'are rigidly secured on a drive shaft 32, the lower arm 20 being relieved at 31 to accommodate the larger cam 38. The shaft 32 is also journaled in the side plates 16 and a pulley 34, or alternatively av crank which is not shown, will be rigidly secured on the shaft 32 to provide driving means for the machine.

A punch 36, best illustrated in Figure 10, is carried on the upper arm 18, this punch having a rectilinear, transverse cutting edge 38 and a pair of elongated, rectangular cutter faces 40 angularly receding from the edge 38. At the outer ends of' the cutter faces 40 are a pair of flat, horizontal, anvil faces 42 which are disposed horizontally and which have a cross-sectional dimension equal to the length of the rectilinear cutting edge 38. The 'forward'end 44 of the upper arm extends forwardly between a pair of lateral guides 46 fixed on the sides of the punch 36 in opposed relation, and guide slots 48 are provided in the side plates 16 to accommodate guides 46 and thus to assure rectilinear, vertical motion of the 'punch 36. In other words, the forward end 44 of the upper arm has a pivotal driving connection with the punch 36. 'Retraction of the punch is accomplished by a cross bar 50 bridging the upper ends of the guides 46 and this bar 50 is engaged by the end portion 44 of the upper arm when the same is raised. The punch 36 has the lower portion removably secured gy a 'set screw '51 to facilitate repair and replacement thereof.

The clincher block 52 is generally Y-shaped with a recessed portion 54 and abutment faces '56 corresponding dimensionally with the anvil faces 42 of the punch. The forward end of the lower arm is provided with lateral guides 58 which slide in arcuate guide slots 60 in the side plates 16 to inhibit any tendency for the clincher block to aberrate from perfect registration with the punch 36. The clincher block is removably secured to r the forward end of the lower arm 20v by a set screw 62.

The side plates are provided with gap slots 64 to define a work-receiving gap for the machine, and the angulated bed plate 66 is integrally and rigidly secured to one of the side plates 16, or this bed plate may be made replaceable by attachment to the side plates by means of any suitable means, if desired. An elongated rectangular opening 68 is provided in the bed plate, the opening 68 corresponding dimensionally with the full horizontal area of the working faces of the punch and clincher block. Otherwise stated, the opening 68 is the same shape and size as the recessed area 54 and abutment plates 56 combined. Minor features can be added to themachine-t adapt'the same for specialized work.

The means for spacing the work pieces will now be described in some detail. A spacer pin 72 is mounted for vertical reciprocatory motion on the machine, this spacer pin being guided by bracket 73 and having a re turned portion 74 extending down through the upper portion of the frame and being guided by a fixed bracket 70 secured to the forward end portion of the frame. A sliding bracket 78 is biased by a spring 88 compresed between the sliding bracket and the fixed bracket- 78 and arranged coaxially on the returned portion 74 of the spacer pin, the mounting of the sliding bracket 78 for vertical sliding movement on the forward end portion of the frame being diagrammatically indicated at 82. A simple gravity type catch 84 is pivotally mounted as indicated at 86, on the upper arm 18. The forward tip of the catch 84 engages the sliding bracket 78 on the upward movement of the arm 18, but the catch 84 is free to ride inoperatively against the sliding bracket 78, when the arm-:is on its downward stroke.

-It-will now-be evidentthat when sheet metal elements 88 are placed upon the bed plate 66 and the machine operated, the upper arm 18 will move fro-m a position approximating that shown in Figure 8 to the full upward position thereof and the catch 84 will then release the sliding bracket 78 and the spacer pin 72 will be forced down by the action of the spring 88 until the lower end of this spacer pin enters into the last preceding aperture 94 formed in the elements 88 by the action of the machine, it being understood, of course, that the spacer pin is only effective after the first clinching cycle has been completed and the work piece moved ahead in the machine. After the first clinching cycle has been completed, the spacer pin will enter each preceding aperture 94 and the spacer pin may be shaped in any suitable manner to engage either end of the aperture 94 or to fit more or less snugly within the aperture according to the desire of the manufacturer of the machine the functioning of the spacer pin being substantially equivalent in any such case. On the downward stroke of the upper arm 18, the catch 84 first rides inoperatively on the sliding bracket 78 and when the lower arm reac'hes the bottom of its downward stroke, the catch 84 falls beneath the sliding bracket as indicated in Figure 7, ready to engage the sliding bracket 78 again on the upward stroke of the upper arm. It will be noted that the spacer pin 72 is not removed from the work piece until the upper arm has moved upwardly sufficiently to withdraw the punch 36 from the work piece.

It will now also be, evident that the punch 36, by reason of its elongated form, will, after first parting the metal in rectilinear line at the center of the punch, then part the elements 68 along two parallel lines while bending the parted metal downwardly as clearly indicated in Figure 4. It is a feature of this invention that this parting of relatively long narrow segments 92 by relatively closely spaced elongated cuts 90, as illustrated in Figure 6 permits the processing of the sheet material without the intervention of a movable bed plate element, yet without undue deformation of the sheet metal elements. Of course, the deletion of a movable bed plate is a considerable advantage and this has been achieved by the instant invention. The next cycle of operation is indicated in Figure 5, with the clincher block 52 being brought into the position shown in that figure and clinching the segments 92 into final position so that the elements are firmly connected together. It should be noted that the clinching action is between the anvil faces 42 and the abutment faces 56, and that no intervening element is required between the confronting pairs of faces of these machine parts.

It is understood that minor variation from the form of the invention disclosed herein may bemade without departure from the spirit and; scope of the invention, and that the specification and drawings are to be considered as merely illustrative rather than limiting.

I claim:

1. A machine for interconnecting sheet metal elements, comprising; a frame having a'bed plate and a fixed head spaced above the bed plate and defining; therewith a work-receiving gap; said bed plate having an elongated rectangular opening therein; a chisel punch operatively mounted in said head to enter and recede from said opening; said chisel punch having a rectilinear, transverse cutting edge and a pair of elongated, rectangular cutter faces having a common boundary at said cutting edge, and a pair of flat anvil faces at the outer ends ofsa d cutter faces; said chisel punch corresponding with said opening in cross-sectional shape anddimenston; a clincher block' operatively mounted on said iframe toapproach and recede from the underside of said bed plate at said opening and having a pair of abutment facesin confronting relation to'said anvil faces; meansforpower driving said chisel 'punchpand meansfor power driv ng said clincher block toward said 'punch when the chisel punch is in the position assumed at the end of the punchmg stroke; whereby long, narrow segments of a pair of sheet metal elements may be parted on three sides, from said elements with a minimum of deformation and residual stress in the elements and said segments clinched to connect said elements together; a work feed control comprising ,a spacer pin reciprocably mounted on said head to span said gap laterally of said chisel punch; said spacer pin being biased to enter the immediately preceding aperture punched by said chisel punch as the work is fed into the machine, thereby arresting the feeding movement of the work while the chisel punch and clincher block operate; means to retract said spacer pin as said chisel punch recedes from said opening, and further means to release said spacer pin when said chisel punch reaches the fully retracted position thereof; said means for power driving comprising a punch-carrying arm pivoted on said frame above said gap, a clincher block-carrying arm pivoted on said frame below said gap, and driven rotary cams operatively mounted on said frame for alternately tilting the first mentioned arm to carry said chisel punch toward and into said aperture and tilting the second mentioned arm to carry said clincher block toward said chisel punch; said means to retract comprising a catch on the first mentioned arm to engage said pin during the retraction movement of the first mentioned arm; said catch disengaging from said pin when the first mentioned arm reaches its fully retracted position.

2. A machine for interconnecting sheet metal elements, comprising: a frame having a bed plate and a fixed head spaced above the bed plate and defining therewith a work-receiving gap; said bed plate having an elongated rectangular opening therein; a chisel punch operatively mounted in said head to enter and recede from said opening; said chisel punch having a rectilinear, transverse cutting edge and a pair of elongated, rectangular cutter faces having a common boundary at said cutting edge, and a pair of substantially horizontal anvil faces at the outer ends of said cutter faces; said chisel punch corre- 6 sponding with said opening in cross-sectional shape and dimension; a clincher block operatively mounted on said frame to approach and recede from the underside of said bed plate at said opening and having a pair of abutment faces in confronting relation to said anvil faces; means for power driving said chisel punch and means for power driving said clincher block toward said chisel punch when the chisel punch is in the position assumed at the end of the punching stroke; whereb y long, narrow segments of a pair of sheet metal elements may be parted, on three sides, from said elements with a minimum of deformation andresidual stress in the elements and said segments clinched to connect said elements together, said means for driving the punch comprising a first arm pivoted on said frame with said chisel punch mounted .on one end of said arm, a second arm pivoted on said frame in opposing relation to said first arm, said clincher block being mounted on the corresponding end of the second arm, and means for moving said arms to carry said chisel punch and clincher block toward and away from each other.

3. A machine according to claim 2 wherein said frame has guide means disposed laterally of said chisel punch and clincher block, and said chisel punch has laterally extending guide means operatively engaging the guide means of the frame, whereby said chisel punch is restricted to rectilinear movement.

4. A machine according to claim 2 wherein said punch has a pair of laterally extending guides, and said frame has side plates with guide channels therein to receive said guides in sliding relation, whereby said chisel punch is restricted to rectilinear motion.

References Cited in the file of this patent UNITED STATES PATENTS 1,569,649 Way Jan. 12, 1926 1,891,767 Ketcham Dec. 20, 1932 

